Thomas Wills

Dr Thomas Wills

Research Fellow

Organisation

University College London

Research summary

We are investigating this problem for the first time in a part of the brain known as the hippocampal formation. The hippocampal formation has a critical function in long-term memory, in particular for episodic memory: memories of particular events, and when and where they happened. The hippocampus also has an important related function: to remember the layout of our environment and navigate around it. Hippocampal damage leaves people not just amnesic, but also particularly prone to disorientation.

To study how the hippocampal formation develops, we observe the activity of individual neurons in behaving rats. The neurons of the hippocampal formation discharge action potentials dependent on the position of the animal allowing us to directly study the neuronal mechanisms underlying its navigation function. (There is also evidence that similar spatial neurons exist in humans). We then manipulate the environment in which the rats grow up, in particular the spatial nature of the environment, and investigate how patterns of neural network activity change during development. Is the development of spatial cells delayed by these manipulations, or is it disrupted permanently?

The results produced by this study will also allow us to better understand hippocampal formation development in humans. Episodic memory develops relatively late in human infants, probably reflecting the slow maturation of the hippocampal formation. Adults cannot recall memories from before 3.5 years of age, a phenomenon referred to as 'childhood amnesia'. Understanding the development of the hippocampal formation at neuronal level in the rat will give us a good handle on understanding these developmental processes in humans.